Correlated k-Distribution Treatment of Cloud Optical Properties and Related Radiative Impact

Peng Lu Chinese Academy of Meteorological Sciences, Beijing, Nanjing University of Information Science and Technology, Nanjing, and Laboratory for Climate Studies, National Climate Center, Beijing, China

Search for other papers by Peng Lu in
Current site
Google Scholar
PubMed
Close
,
Hua Zhang Laboratory for Climate Studies, National Climate Center, Beijing, China

Search for other papers by Hua Zhang in
Current site
Google Scholar
PubMed
Close
, and
Jiangnan Li Canadian Center for Climate Modeling and Analysis, University of Victoria, Victoria, British Columbia, Canada

Search for other papers by Jiangnan Li in
Current site
Google Scholar
PubMed
Close
Restricted access

Abstract

A new scheme of water cloud optical properties is proposed for correlated k-distribution (CKD) models, in which the correlation in spectral distributions between the gaseous absorption coefficient and cloud optical properties is maintained. This is an extension of the CKD method from gas to cloud by dealing with the gas absorption coefficient and cloud optical properties in the same way.

Compared to the results of line-by-line benchmark calculations, the band-mean cloud optical property scheme can overestimate cloud solar heating rate, with a relative error over 30% in general. Also, the error in the flux at the top of the atmosphere can be up to 20 W m−2 at a solar zenith angle of 0°. However, the error is considerably reduced by applying the new proposed CKD cloud scheme. The physical explanation of the large error for the band-mean cloud scheme is the absence of a spectral correlation between the gaseous absorption coefficient and the cloud optical properties. The overestimation of the solar heating rate at the cloud-top layer could affect the moisture circulation and limit the growth of cloud. It is found that the error in the longwave cooling rate caused by the band-mean cloud scheme is very small. In the infrared, the local thermal emission strongly affects the spectral distribution of the radiative flux, which makes the correlation between the gaseous absorption coefficient and cloud optical properties very weak. Therefore, there is no obvious advantage in emphasizing the spectral correlation between gas and cloud.

Corresponding author address: Dr. Jiangnan Li, Canadian Center for Climate Modeling and Analysis, University of Victoria, P.O. Box 3065, Victoria BC V8W 3V6, Canada. E-mail: jiangnan.li@ec.gc.ca

Abstract

A new scheme of water cloud optical properties is proposed for correlated k-distribution (CKD) models, in which the correlation in spectral distributions between the gaseous absorption coefficient and cloud optical properties is maintained. This is an extension of the CKD method from gas to cloud by dealing with the gas absorption coefficient and cloud optical properties in the same way.

Compared to the results of line-by-line benchmark calculations, the band-mean cloud optical property scheme can overestimate cloud solar heating rate, with a relative error over 30% in general. Also, the error in the flux at the top of the atmosphere can be up to 20 W m−2 at a solar zenith angle of 0°. However, the error is considerably reduced by applying the new proposed CKD cloud scheme. The physical explanation of the large error for the band-mean cloud scheme is the absence of a spectral correlation between the gaseous absorption coefficient and the cloud optical properties. The overestimation of the solar heating rate at the cloud-top layer could affect the moisture circulation and limit the growth of cloud. It is found that the error in the longwave cooling rate caused by the band-mean cloud scheme is very small. In the infrared, the local thermal emission strongly affects the spectral distribution of the radiative flux, which makes the correlation between the gaseous absorption coefficient and cloud optical properties very weak. Therefore, there is no obvious advantage in emphasizing the spectral correlation between gas and cloud.

Corresponding author address: Dr. Jiangnan Li, Canadian Center for Climate Modeling and Analysis, University of Victoria, P.O. Box 3065, Victoria BC V8W 3V6, Canada. E-mail: jiangnan.li@ec.gc.ca
Save
  • Abramowitz, M., and I. Stegun, 1972: Handbook of Mathematical Functions with Formulas, Graphs, and Mathematical Tables. Dover, 1046 pp.

  • Cess, R., and Coauthors, 1995: Absorption of solar radiation by clouds: Observations versus models. Science, 267, 496499.

  • Chou, M.-D., and M. J. Suarez, 1999: A solar radiation parameterization for atmospheric studies. NASA Tech. Memo. 104606, Vol. 15, 40 pp.

    • Search Google Scholar
    • Export Citation
  • Chou, M.-D., M. J. Suarez, C.-H. Ho, M. M.-H. Yan, and K.-T. Lee, 1998: Parameterizations for cloud overlapping and shortwave single-scattering properties for use in general circulation and cloud ensemble models. J. Climate, 11, 202214.

    • Search Google Scholar
    • Export Citation
  • Chou, M.-D., M. J. Suarez, X.-Z. Liang, and M. M.-H. Yan, 2001: A thermal infrared radiation parameterization for atmospheric studies. NASA Tech. Memo. 104609, Vol. 19, 56 pp.

    • Search Google Scholar
    • Export Citation
  • Chylek, P., and V. Ramaswamy, 1982: Simple approximation for infrared emissivity of water clouds. J. Atmos. Sci., 39, 171177.

  • Chylek, P., P. Damiano, and E. P. Shettle, 1992: Infrared emittance of water clouds. J. Atmos. Sci., 49, 14591472.

  • Clough, S. A., M. W. Shephard, E. J. Mlawer, J. S. Delamere, M. J. Iacono, K. Cady-Pereira, S. Boukabara, and P. D. Brown, 2005: Atmospheric radiative transfer modeling: A summary of the AER codes. J. Quant. Spectrosc. Radiat. Transfer, 91, 233244.

    • Search Google Scholar
    • Export Citation
  • Dobbie, J. S., J. Li, and P. Chylek, 1999: Two- and four-stream optical properties for water clouds and solar wavelengths. J. Geophys. Res., 104, 20672079.

    • Search Google Scholar
    • Export Citation
  • Edwards, J., and A. Slingo, 1996: Studies with a flexible new radiation code. I: Choosing a configuration for a large-scale model. Quart. J. Roy. Meteor. Soc., 122, 689720.

    • Search Google Scholar
    • Export Citation
  • Espinoza, R. C., and Harshvardhan, 1996: Parameterization of solar near-infrared radiative properties of cloudy layers. J. Atmos. Sci., 53, 15591568.

    • Search Google Scholar
    • Export Citation
  • Fomin, B., and M. P. Correa, 2005: A k-distribution technique for radiative transfer simulation in inhomogeneous atmosphere: 2. FKDM, fast k-distribution model for the shortwave. J. Geophys. Res., 110, D02106, doi:10.1029/2004JD005163.

    • Search Google Scholar
    • Export Citation
  • Fu, Q., and K. N. Liou, 1992: On the correlated k-distribution method for radiative transfer in nonhomogeneous atmospheres. J. Atmos. Sci., 49, 21392156.

    • Search Google Scholar
    • Export Citation
  • Goody, R. M., and Y. L. Yung, 1989: Atmospheric Radiation: Theoretical Basis. 2nd ed. Oxford University Press, 544 pp.

  • Hollweg, H.-D., 1993: A k-distribution method considering centres and wings of atmospheric absorption lines. J. Geophys. Res., 98, 27472756.

    • Search Google Scholar
    • Export Citation
  • Hu, Y. X., and K. Stamnes, 1993: An accurate parameterization of the radiative properties of water clouds suitable for use in climate models. J. Climate, 6, 728742.

    • Search Google Scholar
    • Export Citation
  • Kato, S., T. Ackerman, J. Mather, and E. Clothiaux, 1999: The k-distribution method and correlated-k approximation for a shortwave radiative transfer model. J. Quant. Spectrosc. Radiat. Transfer, 62, 109121.

    • Search Google Scholar
    • Export Citation
  • Kratz, D., 1995: The correlated k-distribution technique as applied to the AVHRR channels. J. Quant. Spectrosc. Radiat. Transfer, 53, 501517.

    • Search Google Scholar
    • Export Citation
  • Lacis, A. A., and V. Oinas, 1991: A description of the correlated k distribution method for modeling nongray gaseous absorption, thermal emission, and multiple scattering in vertically inhomogeneous atmosphere. J. Geophys. Res., 96, 90279063.

    • Search Google Scholar
    • Export Citation
  • Li, J., 2002: Accounting for unresolved clouds in a 1D infrared radiative transfer model. Part I: Solution for radiative transfer, including cloud scattering and overlap. J. Atmos. Sci., 59, 33023320.

    • Search Google Scholar
    • Export Citation
  • Li, J., and H. W. Barker, 2005: A radiation algorithm with correlated-k distribution. Part I: Local thermal equilibrium. J. Atmos. Sci., 62, 286309.

    • Search Google Scholar
    • Export Citation
  • Li, J., J. G. D. Wong, J. S. Dobbie, and P. Chylek, 2001: Parameterization of the optical properties and growth of sulfate aerosols. J. Atmos. Sci., 58, 193209.

    • Search Google Scholar
    • Export Citation
  • Li, J., C. L. Curry, Z. Sun, and F. Zhang, 2010: Overlap of solar and infrared spectra and the shortwave radiative effect of methane. J. Atmos. Sci., 67, 23722389.

    • Search Google Scholar
    • Export Citation
  • Lindner, T. H., and J. Li, 2000: Parameterization of the optical properties for water clouds in the infrared. J. Climate, 13, 17971805.

    • Search Google Scholar
    • Export Citation
  • McClatchey, R., R. Fenn, J. A. Selby, F. Volz, and J. Garing, 1972: Optical Properties of the Atmosphere. 3rd ed. Air Force Cambridge Research Laboratories, 108 pp.

    • Search Google Scholar
    • Export Citation
  • Mlawer, E., and S. Clough, 1998: Shortwave and longwave enhancements in the rapid radiative transfer model. Proc. Seventh Atmospheric Radiation Measurement (ARM) Science Team Meeting, San Antonio, TX, U.S. Department of Energy. [Available online at http://www.arm.gov/publications/proceedings/conf07/extended_abs/mlawer_ej.pdf.]

    • Search Google Scholar
    • Export Citation
  • Mlawer, E., S. Taubman, P. Brown, M. Iacono, and S. Clough, 1997: Radiative transfer for inhomogeneous atmosphere: RRTM, a validated correlated-k model for the longwave. J. Geophys. Res., 102, 16 66316 682.

    • Search Google Scholar
    • Export Citation
  • Nakajima, T., M. Tsukamoto, Y. Tsushima, A. Numaguti, and T. Kimura, 2000: Modeling of the radiative process in an atmospheric general circulation model. Appl. Opt., 39, 48694878.

    • Search Google Scholar
    • Export Citation
  • Räisänen, P., 1999: Parameterization of water and ice cloud near-infrared single-scattering co-albedo in broadband radiation schemes. J. Atmos. Sci., 56, 626641.

    • Search Google Scholar
    • Export Citation
  • Ramanathan, V., R. D. Cess, E. F. Harrison, P. Minnis, B. R. Barkstrom, E. Ahmad, and D. Hartmann, 1989: Cloud-radiative forcing and climate: Results from the Earth Radiation Budget Experiment. Science, 243, 5773.

    • Search Google Scholar
    • Export Citation
  • Ramaswamy, V., and S. M. Freidenreich, 1992: A study of broadband parameterizations of the solar radiative interactions with water vapor and water drops. J. Geophys. Res., 97, 11 48711 512.

    • Search Google Scholar
    • Export Citation
  • Rothman, L. S., and Coauthors, 2009: The HITRAN 2008 molecular spectroscopic database. J. Quant. Spectrosc. Radiat. Transfer, 110, 533572.

    • Search Google Scholar
    • Export Citation
  • Segelstein, D., 1981: The complex refractive index of water. M.S. thesis, Dept. of Physics, University of Missouri at Kansas City, 167 pp.

    • Search Google Scholar
    • Export Citation
  • Slingo, A., 1989: A GCM parameterization for the shortwave radiative properties of water clouds. J. Atmos. Sci., 46, 14191427.

  • Zhang, H., T. Nakajima, G. Shi, T. Suzuki, and R. Imasu, 2003: An optimal approach to overlapping bands with correlated k distribution method and its application to radiative transfer calculations. J. Geophys. Res., 108, 4641, doi:10.1029/2002JD003358.

    • Search Google Scholar
    • Export Citation
  • Zhang, H., G. Shi, T. Nakajima, and T. Suzuki, 2006a: The effects of the choice of the k-interval number on radiative calculations. J. Quant. Spectrosc. Radiat. Transfer, 98, 3143.

    • Search Google Scholar
    • Export Citation
  • Zhang, H., T. Suzuki, T. Nakajima, G. Shi, X. Zhang, and Y. Liu, 2006b: The effects of band division on radiative calculations. Opt. Eng., 45, 016002, doi:10.1117/1.2160521.

    • Search Google Scholar
    • Export Citation
  • Zhang, M. H., and Coauthors, 2005: Comparing clouds and their seasonal variations in 10 atmospheric general circulation models with satellite measurement. J. Geophys. Res., 110, D15S02, doi:10.1029/2004JD005021.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 514 201 43
PDF Downloads 185 39 3